Tubular structure



Sept 26, 1961 c. R. STRAUBING 3,001,767

TUBULAR STRUCTURE Filed Nov. 16, 1959 2 Sheets Sheet l @@QQM ATTORNEY Sept 26, 1961 c. R. sTRAUBlNG 3,001,767

TUBULAR STRUCTURE Filed Nov. 16, 1959 2 Sheets-Sheet 2 INVENTOR Charles Rmurzlrlg BY caw ATTORNEY United States Patent 3,091,767 Patented Sept. 26, 1961 3,001,767 TUBULAR' STRUCTURE Charles R. Straubing, Sodus Point, N.Y., assigner to Kenmore Machine Products, Inc., Lyons, N.Y., a corporation of New York Filed Nov. 16, 1959, Ser. No. 853,162 1 Claim. (Cl. 257-246) The present invention relates to a tubular structure and it consists in the combinations, constructions and arrangements of parts herein described and claimed.

Generally there is provided -a novel tubular structure which, as illustrated herein, may be utilized as a heat exchanger but which may serve other purposes'and a novel method for joining the registering end portions of an inner and an outer tube forming such structure. The method involves the positioning of a tube of relatively small diameter within a tube of greater diameter with the tube ends portions registering and thereafter joining the registered end portions by spinning the same in a die in such manner that the metals of the two tubes flow together at such end portions to permanently interconnect the same without the use, as is customary, of brazing or welding.

Another object of the invention is to provide novel spacing means between the inner and outer walls of a tubular structure of the character set forth.

Another object of the invention is to provide a novel sleeve structure for a tubular heat exchanger forming a part ofthe invention.

Another object of the invention is to provide a novel structure of the character set forth which is simple in construction, inexpensive to manufacture and yet effective and eicient in use.

Still another object of the invention is to provide a sleeve of the character set forth having novel means for forcing uid passing thereover to take a sinuous path to thereby provide greater efficiency when the device is utilized as a heat exchanger.

Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the drawings, in which:

FIGURE 1 is a perspective view of a tubular structure made in accordance with the teachings of the present invention,

FIGURE 2 is an enlarged fragmentary vertical sectional view, partly in elevation, of the device illustrated in FIGURE 1,

FIGURE 3 is a sectional view, partly in elevation, taken along line 3-3 of FIGURE 2 but showing a sleeve forming a part of the invention removed therefrom,

FIGURE 4 is a sectional view taken along line 4--4 of FIGURE 2,

FIGURE 5 is a View similar to FIGURE 2 but illustrating another form the invention may assume,

FIGURE 6 is an enlarged fragmentary elevational view of a novel sleeve forming a part of the invention,

FIGURE 7 is an end elevational View taken substantially along line 7-7 of FIGURE 6,

FIGURE 8 is an end elevational View of a die utilized in carrying out the present invention, and

FIGURE 9 is a fragmentary sectional view partly in elevation, illustrating the manner of carrying out method of the present invention.

Referring more particularly to the drawings, there is shown vtherein a tubular structure formed of an elongated inner tube 10 and an outer tube 11 of comparatively greater diameter than the tube 10 but of identical length therewith.

Adjacent each end of the outer tube 11 there is provided a flattened portion 112 having a fitting 13 axed thereto whereby a pipe 14 may be connected therewith.

A sleeve member is generally designated at 15 and is interposed between the tubes 10 and 11 in such manner as to snugly fit against the adjacent walls of the tubes 10 and 11. The sleeve member is'designed to provide a circuitous path for fluids passing from one of the pipes 14 to the other of such pipes. The sleeve member 15 is preferably, and as shown, composed of two identical semi-cylindrical parts 16 and 17 for the purpose of simplicity of manufacture and assembly. It will be noted that each of the parts 16 and 17 of the sleeve 15 is longitudinally undulated and provided with a staggered pattern of protuberances 18 and indentations 19 as clearly shown in FIGURES 6 and 7 and it will be further noted that the indentations bear against the outer wall of the inner tube 10 while the protuberances 18 bear against the inner wall of the other tube 11 thus forcing fluid passing from one pipe 14 to the other to pass around the same thus forcing a longer path through such iiuid and greatly enhancing the heat exchange powers of the device as a whole.

In FIGURE 5, no sleeve is provideed but circular spacer members 2|) are interposed between the inner and outer tubes 10 and 11 in positions adjacent either end of the device. The members 20 are preferably and as shown of U-shaped cross sectional -area with their bight portions 21 interconnecting the leg portions 22 thereof which latter are in abutting relation to the adjacent walls of the tubes 10 and 11.

In joining the adjacent registering ends of the inner and outer tubes 10 and 11, a rotatable die 23, as illustrated in FIGURE 9 is provided and it will be seen that the registering end portions o-f the inner and' outer tubes 10 and 11 are forced into the die 23 and it will be apparent that the heat of friction of the die 23 rotating rapidly against such end portions of the tubes 10 and 11 will cause the end portions thereof to weld together in a quick and eiiicient manner, thus making the use of brazing, soldering or conventional welding unnecessary while at the same time providing a complete and efficient sealing and joining of such end portions. This process is, of course, repeated at the other end of the device to completely join and seal together the inner and outer tube members 10 and 11.

While but certain forms of the invention have been shown and described herein, it will be readily apparent to those skilled in the art that many minor modifications may be made without departing from the spirit of the invention or the scope of the appended claim.

What is claimed is:

A tubular structure comprising an inner tube, an outer tube of greater diameter throughout its central portion and permanently aiiixed to said inner tube at their end portions, a pair of pipe fittings each mounted in said outer tube adjacent an opposite end portion thereof, and

the

a pair of imperforate semi-cylindrical sleeves extending through the central portion of said structure medially between and in good heat-exchange contact with the adjacent walls of said tubes, said semi-cylindrical sleeves having a plurality of longitudinally and' circumferentially spaced indentations alternating with a plurality of longitudinally and circumferentially spaced protuberances each having relatively large and. flat end portions providing said good heat-exchange Contact with said adjacent tube walls, said indentations and protuberances being in staggered patterns to provide longer circuitous Huid-How paths on both sides of said semi-cylindrical sleeves and the sleeve portions between said indentatons and protuberances being longitudinally undulated for further increasing the turbulence of the fluid-flow and thus im- 5 proving the heat transfer.

References Cited in the le of this patent UNITED STATES PATENTS 2,752,128 Dedo June 26, 1956 10 2,756,032 Dowell July 24, 1956 2,959,400 Simpelaar Nov. 8, 1960 

